Is there a critical level of plantar foot pressure to identify patients at risk for neuropathic foot ulceration?

The purpose of this study was to identify a point along the spectrum of peak plantar forefoot pressure that has an optimum combination of sensitivity and specificity to screen for neuropathic ulceration. We enrolled 219 diabetic patients in this case-control study in an approximate 2:1 control:case ratio. Cases were defined as patients with an active or recently healed neuropathic ulceration. Controls were defined as those with no history of ulceration. All patients had peak plantar pressures analyzed with the EMED gait analysis system. Peak plantar pressure was, as expected, significantly higher for patients with ulcers compared to controls [83.1 +/- 24.7 N/cm2 (range, 10-125) vs. 62.7 +/- 24.4 N/cm2 (range, 7.3-113), p < .001]. The ulcer group was clearly skewed toward a higher prevalence of elevated peak plantar forefoot pressure compared with the control group, which displayed the opposite trend (control group skewness = 0.286, kurtosis = -0.482; ulcer group skewness = -0.389, kurtosis = -0.289). Using receiver operating characteristic analysis, the optimal cut-point, as determined by a balance of sensitivity and specificity was 70 N/cm2, which yielded a sensitivity of 70.0% and a specificity of 65.1%. We concluded that, while there is no optimal cut-point for clearly screening patients for risk of foot ulceration, the higher the peak pressure, the higher the commensurate risk.